JP2810514B2 - Bar code reader and its inspection method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Overview] A bar code reader for optically reading a bar code and a method for inspecting the bar code are provided. In a bar code reader that optically reads a bar code and outputs a code signal corresponding to the bar code, whether the code signal obtained by reading the bar code corresponds to a specific bar code. A code discriminating means for discriminating whether or not the bar code reading device has an internal processing when the specific bar code is discriminated by the code discriminating means. Be composed.

[Industrial applications]

The present invention relates to a bar code reader for optically reading a bar code and an inspection method therefor.

In recent years, the introduction of POS systems in various stores and the adoption of factory automation (FA) have advanced, and barcodes have been widely used to identify articles. Accordingly, it is desired to improve the mass productivity of the barcode reader and to facilitate maintenance.

[Conventional technology]

For example, a stationary bar code reader used as a product identification means of a POS system such as a supermarket scans a bar code standardized by JIS-X0501 or the like with a laser beam and reads the bar code. It is configured to output a code signal indicating a digit number to an external device such as a cash register.

Conventionally, in a barcode reader, a plurality of types of output interfaces are incorporated so that connection with a plurality of types of external devices having different signal transmission formats is possible. One output interface can be selected by switching a dip switch or the like. That is, the output format of the code signal can be changed according to the external device.
Thereby, in configuring the POS system, the degree of freedom in selecting the model of the external device (combination of the barcode reader and the external device) is increased.

[Problems to be solved by the invention]

The selection of the output interface described above is performed when the barcode reader is shipped from the manufacturing factory, or when the barcode reader is installed in a store or the like and connected to an external device. At this time, conventionally, in order to switch a dip switch or the like, it is necessary to remove the outer cover of the bar code reader to expose the electric circuit portion, and there has been a problem that much work and time are required for the operation.

Generally, in a bar code reader, the deterioration of the laser light source greatly affects the reading performance among the aging of each part. Therefore, at the time of maintenance, it is necessary to determine whether or not the laser light source needs to be replaced. Therefore, conventionally, a serviceman detached the barcode reader from the support (reading table) and measured the laser output.

That is, in the related art, there has been a problem that much labor and time are required for the work at the time of maintenance.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to facilitate operations for maintenance of an operation state in shipping adjustment or maintenance and inspection after production is completed.

[Means for solving the problem]

The apparatus according to claim 1 is a bar code reader that optically reads a bar code and outputs a code signal D1 corresponding to the bar code, wherein the code signal D1 obtained by reading the bar code is: A code discriminating unit 33 for discriminating whether or not the barcode reading device 1 corresponds to a specific barcode 71 defined as information for instructing execution of internal processing for maintenance of the barcode reader 1; When the specific barcode 71 is determined, an internal processing executing means 34 for executing internal processing for maintenance of the barcode reader 1 is provided.

The device according to claim 2, wherein a plurality of output interfaces 35 to 39 for outputting the code signal D1 to the outside, and a code signal D1 obtained by reading a bar code are output to the output interfaces 35 to 39 in advance. Code discriminating means for discriminating whether or not it corresponds to a specific barcode 71 defined as information for instructing selection of one output interface 35 of the
33, when the specific barcode 71 is determined by the code determination unit 33, the output interface 35 to
Interface selecting means 34 for selecting one output interface 35 corresponding to the specific barcode 71 out of 39.

The method according to the third aspect of the present invention is a method for inspecting a bar code reader 1 having a light source 21 for reading a bar code, wherein the bar code indicates predetermined specific information and the size of the bar code is an allowable limit value. A test barcode 72 is read, and the light source 21 is read depending on the success or failure of reading the specific information.
Is determined.

(Operation)

The code determining unit 33 determines whether the code signal D1 corresponds to the specific barcode 71.

When the read barcode is determined to be the specific barcode 71, the internal processing executing means 34 executes internal processing for maintenance of the barcode reader 1. The output interface 35 to the output interface 35 to
One output interface 35 corresponding to the specific barcode 71 out of 39 is selected.

If the specific information is correctly read from the test barcode 72 with the size of the barcode indicating the specific information as the allowable limit, the reading resolution is within the allowable range and the light source
21 can be determined to be good. If the specific information cannot be read correctly, the light source 21
Can be determined to be defective.

〔Example〕

 Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of the barcode reader 1 according to the present invention.

The bar code reader 1 is composed of a power supply unit 10 for supplying drive power to each unit, an optical system 20, a signal processing unit 30, and the like, and a register 2 (cash register) as an external device via a connector 40 and a cable 3. It is connected.

The optical system 20 includes a laser tube 21 for emitting He-Ne laser light, a scanning unit 22 including a polygon mirror for deflecting the laser light, and a photoelectric conversion unit 23. The signal processing unit 30 includes an A / D conversion unit 31, a demodulation unit 32,
It comprises a specific code control section 33 unique to the present invention and an external output section 34.

The external output unit 34 includes five interfaces 35 to 35 having different signal output formats as output interfaces.
39 can be switched alternatively. That is, the signal output formats of the interfaces 35 to 39 are a general-purpose serial output, a communication RS232C output, a general-purpose parallel output, a specific model multi-output, and a specific model parallel output, respectively.
The selection is made according to the signal input format of the register 2.

A normal reading operation of the barcode reader 1 configured as described above will be described.

When the product with the bar code passes above the hologram window (reading window) 60, the bar code is scanned by the scanning unit 22, and the reflected light from the bar code enters the photoelectric conversion unit 23. The photoelectric conversion unit 23 converts the reflected light corresponding to the black and white level of the barcode into an analog signal S0. The analog signal S0 is binarized by the A / D converter 31 and is supplied to the demodulation unit 32 as pulse data D0.

The demodulation unit 32 detects a pulse width and a pulse interval of the pulse data D0, and determines a numerical value of each digit of a predetermined number of digits indicated by a bar code from the detection result. Then, as a reading check process (misreading prevention process), based on the determined numerical value, for example, a numerical value obtained by a calculation method called “modulus 10” is compared with a numerical value of a check digit (the first digit at the right end). I do. If these values match, the display unit 50 displays the success of barcode reading, and if they do not match, the display unit 50 displays failure of barcode reading. The display unit 50 displays the success of reading by, for example, lighting of a green lamp and a signal sound, and displays the failure of reading by, for example, lighting of a red lamp and a signal sound.

When the reading is successful, the demodulation unit 32 outputs the determined numerical value of each digit as a code signal D1, and the code signal D1 is sent to the register 2 via the external output unit.

On the other hand, the register 2 determines the item (item) of the product from the code signal D1 input via the connector 2c, and inquires the central management device (store controller) (not shown) about the price of the product. Then, when the price data is sent from the store controller, the price is displayed on the display 2a, and the item and the price are printed by the printer 2b. Note that the barcode may include information indicating the price.

Next, the interface 35 in the barcode reader 1
The selection of Nos. To 39 will be described.

In the above description, the barcode reader 1
However, in the manufacturing stage of the barcode reader 1, the external device to be connected is not always specified. Therefore, when the external device is specified, it is necessary to select the interfaces 35 to 39 that match the external device.

When selecting such interfaces 35 to 39,
In the barcode reader 1, the interface 35 to be selected
A specific barcode 71 including information indicating .about.39 is used.

That is, the operator arranges the barcode 71 above the hollow window 60 and causes the barcode 71 to be read in the same manner as when reading a normal barcode.

The specific code control unit 33 compares the code signal 1 output from the demodulation unit 32 with a specific code stored in advance, and determines that the read barcode is a specific barcode 71.
Is determined, and if the barcode is a specific barcode 71, the external output unit 34 is instructed to select one of the interfaces 35 to 39. In response, the external output unit 34 selects one of the interfaces 35 to 39 according to the barcode 71. For example, when the barcode 71 corresponds to the interface 35, the external output unit 34 selects the interface 35.

That is, since the barcode reader 1 is provided with five interfaces 35 to 39, five types of barcodes 71 corresponding to the respective interfaces 35 to 39 are prepared for selection of an external output format. A predetermined barcode 71 is used according to the interfaces 35 to 39 to be set.

In addition, the bar code 71 indicates that the check digit is
This is a value obtained by adding “1” to the value calculated by “modulus 10”, whereby the specific code control unit 33 sets the bar code 71 for internal processing different from a normal product identification bar code (for selecting an interface). ) Bar code.

The selection of the interfaces 35 to 39 in the external output unit 34 is performed by rewriting the storage contents of a memory switch composed of a nonvolatile memory according to the selection.

When the selection of the interfaces 35 to 39 is completed by the external output unit 34, the display unit 50 generates a signal sound or blinks the amplifier according to the newly selected interfaces 35 to 39. When an external device such as the register 2 is connected, the newly selected interfaces 35 to 35 are connected.
A code signal D1 indicating 39 is output to the external device. Thereby, the operator can confirm which interface 35 to 39 is selected by the display unit 50 or the display 2a of the register 2.

As described above, in the barcode reader 1, the interfaces 35 to 39 can be switched only by reading the barcode 71 without removing the outer cover.
In other words, the operation for maintaining the barcode reader 1 suitable for its use environment is simple.

Subsequently, an inspection method of the barcode reader 1 according to the present embodiment will be described.

 FIG. 2 is a diagram showing the operation of the A / D converter 31.

In general, in a bar code reader, when the use time is long, the number of failures in reading is slightly increased. The cause is firstly contamination of the reading window, and secondly, a decrease in the amount of laser light due to deterioration of the laser light source.

Therefore, in the maintenance of the barcode reader 1, first, the surface of the hollow window 60 is cleaned, and thereafter, the inspection focusing on the laser tube 21 is performed.

As is well known, JIS-X0501 requires the bar code dimension to be 0.8% of the standard value (module size is 0.33 mm).
Values reduced or enlarged in a range of up to 2 times are standardized, and tolerances of bar widths and bar intervals are determined according to the magnification. For example, when the magnification is 0.8, the module size is 0.264 mm, and the tolerance of the width of one bar including 1 to 4 modules is ± 0.035 mm.

In the barcode reader 1, the demodulation unit 32 outputs the pulse data D0 if the size of the barcode to be read is within an allowable range.
It is configured such that the code information can be reliably identified from.

Therefore, as an inspection of the bar code reader 1, a test bar code 72 in which the dimensions of each part of the black bar 72a and the white bar 72b shown in FIG. Note that the information represented by the barcode 72 can be arbitrarily determined. Here, it is assumed to represent, for example, a 13-digit number. The barcode 72 is provided by etching a mirror-finished stainless steel plate using a photolithography method in order to obtain high-precision dimensions that are difficult to print and to suppress aging. That is, the portion that has been roughened (irregular reflection surface) by etching corresponds to the black bar 72a, and the portion that remains as a mirror surface is the white bar 7a.
It corresponds to 2b.

When such a barcode 72 is scanned, the photoelectric conversion unit
From 23, the analog signal S0 shown in FIG. 2B is output according to the black bar 72a and the white bar 72b. At this time, if the output of the laser tube 21 is normal, the analog signal S0 becomes a signal having a predetermined dynamic range as shown by a solid line in the figure. However, as the output of the laser tube 21 decreases, the signal level of the analog signal S0 decreases as shown by a broken line in FIG.

In the A / D converter 31, since the analog signal S0 is binarized at a predetermined threshold level th, if the output of the laser tube 21 is normal, as shown in FIG. The pulse data D0 having a pulse width corresponding to the bar widths of the black bar 72a and the white bar 72b is output, and the bar code 72 is successfully read. However, if the output of the laser tube 21 decreases to a certain level or less, the second As shown in FIG. (C2), the pulse data D0 that does not correspond to the barcode 72 is output and reading fails.

Therefore, the operator (serviceman or user) can confirm whether the reading of the barcode 72 is successful or not on the display unit 50, thereby knowing whether or not the laser tube 21 is deteriorated enough to require replacement.

According to the above inspection method, the quality of the laser tube 21 can be confirmed only by reading the barcode 72 without removing the barcode reader 1 from a support such as a cashing counter in a store. That is, the maintenance work of the barcode reader 1 is simplified.

According to the above-described embodiment, it is not necessary to provide a mechanical component such as a dip switch for selecting an external output format.
Can be reduced in size.

In the above-described embodiment, after the selection of the interfaces 35 to 39 is completed, in order to return the operating state of the barcode reader 1 to the normal reading state, the return barcode is read, and the specific code control unit 33 is operated. The return barcode may be determined. Also the interface
After the selection of 35 to 39, the normal reading state may be restored after a predetermined time has elapsed.

In the above-described embodiment, when the barcode 71 is read, the selection of the interfaces 35 to 39 is performed. However, as an internal process for maintenance of the barcode reader 1, for example, A / D conversion Adjustment of the threshold level th of the vessel 31;
The setting of the signal tone of the display unit 50 and the check of the identification logic of the demodulation unit 32 may be performed.

Further, a check process of the laser tube 21 may be executed. In that case, the first specific barcode is determined by the specific code control unit 33, the demodulation unit 32 is switched to the test mode, and the pulse data D0 when the second specific barcode is scanned is stored in advance. The difference between the pulse width and the reference data thus set can be output as the code signal D1. According to this, the degree of deterioration of the laser tube 21 can be known by a numerical value on the display 2a of the register 2.

〔The invention's effect〕

ADVANTAGE OF THE INVENTION According to this invention, the operation | work for maintenance of an operation state in shipping adjustment after maintenance completion, a maintenance check, etc. can be facilitated.

According to the second aspect of the invention, the work of switching the signal output format to the outside becomes easy.

According to the third aspect of the present invention, the quality of the light source can be easily confirmed.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a barcode reader according to the present invention, and FIG. 2 is a diagram showing an operation of an A / D converter. In the figure, 1 is a barcode reader (barcode reader), 21 is a laser tube (light source), 33 is a specific code control section (code discriminating means), 34 is an external output section (internal processing executing means, interface selecting means). , 35 to 39 are interfaces (output interfaces), 71 is a bar code (specific bar code), 72 is a bar code (test bar code), and D1 is a code signal.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G06K 7/10

Claims (3)

(57) [Claims] 1. A bar code reading device for optically reading a bar code and outputting a code signal corresponding to the bar code, wherein the code signal obtained by reading the bar code is provided in advance in the maintenance of the bar code reading device. Code discriminating means for discriminating whether or not the barcode corresponds to a specific barcode defined as information for instructing execution of internal processing for the barcode, when the specific barcode is discriminated by the code discriminating means, A bar code reader comprising: an internal processing executing means for executing internal processing for maintenance of the code reader. 2. A bar code reader for optically reading a bar code and outputting a code signal corresponding to the bar code, comprising: a plurality of output interfaces for outputting the code signal to the outside; Code discriminating means for discriminating whether or not the obtained code signal corresponds to a specific barcode previously determined as information for instructing selection of one of the output interfaces, Means for selecting one output interface corresponding to the specific barcode from the output interfaces when the specific barcode is determined by the means. Reader. 3. A method of inspecting a bar code reader having a light source for reading a bar code, the method comprising reading a test bar code indicating predetermined specific information and having a size of the bar code as an allowable limit value. And determining whether the light source is good or bad based on the success or failure of the reading of the specific information.